textproduct: Quad Cities

KEY MESSAGES

- There is a Slight (level 2 out of 5) risk for severe weather late this afternoon/evening west of a line from Dubuque to Keokuk. Damaging wind will be the primary threat.

- Dry weekend, with a return of active weather early next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 251 AM CDT Thu Apr 23 2026

Early morning water vapor loop depicts strong negatively tilted shortwave rotating over eastern MT. To the east of this wave, surface observations and RAP analysis has 983mb surface low along the US-Canada border with a cold front extending south to another low over northwest KS. Radar mosaics have showers and thunderstorms along this front across the Dakotas and northern NE. Meanwhile closer to home, a lake enhanced boundary was just to our northeast with dewpoints in the upper 30s/40s and temps in the 50s over northeast IL. Locally, mild temperatures were reported with readings in the upper 50s/low 60s.

A warm and breezy day is expected today, with storm chances/severe potential arriving late afternoon and evening. Will break down the forecast and hazards below.

Temperature/Wind

The aforementioned surface low over northwest KS and associated cold front to track northeast towards Sioux Falls, SD early this afternoon. Strong WAA will take place in the warm sector (entire CWA) evident by the 30-35 kts in the 925-850mb layer. In addition, forecast soundings show another day of deep mixing at least up to 850mb, with 35kts at top of mixed layer. This results in widespread highs in the upper 70s/low 80s and southerly winds gusting 35-40 mph at times this afternoon/evening. Have also lowered afternoon Tds some in anticipation of deep mixing that should bring a slightly less unstable environment this afternoon, but still enough to warrant a severe risk. If we mix even further as is suggested by the latest RAP, some mid 80s will be possible which would be near a record high for BRL today. See climate section below for details.

Severe Risk

SPC has maintained its Slight or level 2 of 5 risk for severe weather today. An EML plume will keep the forecast area dry through at least 18z, before a pre-frontal trough allows for a few isolated/scattered cells to develop ahead of the main line. 00z deterministic and ensemble CAMs have mixed signals as to when this may happen likely as a result of too high afternoon Td's and subsequent instability values for several of the 00z runs (ARW/NSSL/NamNest). Have discounted these solutions for now and went more with 00z REFS >40 dbZ paintballs which has CI occurring in the 20-23z northwest of a Fairfield to Maquoketa line. SBCAPEs around 2000 J/Kg, 0-6km shear values 30-35kts, steep mid-level lapse rates, and FZL around 11kft to bring a small hail/severe wind risk with these initial cells. Can't completely rule out a tornado as well with LCLs lowering under 1kft and a noticeable backing low level wind profile as shown in the 06z RAP.

Attention then turns to the main front/stronger forcing supporting a line of storms racing across Iowa this evening. Timing has not changed much with this activity which should reach the western CWA border between 03-04z. Surface instability will quickly wane each hour going forward and with it the severe risk diminishes. However, an increasing LLJ should allow storms to continue through the early morning hours Friday. Any bowing segment prior to midnight, could bring severe wind but coverage should be rather limited. Rainfall amounts will largely fall within the 0.4" to 0.7" range, higher amounts favored in our northwest third. Some locally higher amounts over 1" also possible for areas that see repeated rounds of thunderstorms.

After midnight through sunrise Friday, decaying convection is expected, with only scattered QPF over 0.10 possible.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 251 AM CDT Thu Apr 23 2026

An upper level low over south-central Canada will bring seasonable conditions and additional precipitation chances through next week before moving to the east.

Showers and some thunderstorms will linger through Friday morning as the cold front continues to move through the region. Following the frontal passage, Friday evening and Saturday will be clear and dry due to subsidence associated with the 500mb jet around the upper level trough. Highs are expected to remain a few degrees above normal at around 70 degrees.

The next chances for precipitation will come Sunday into Monday as an embedded shortwave translates through the upper level flow. At this point, the greatest uncertainty lies in the track of the associated surface low. Current ensemble mean forecasts place the surface low over eastern Iowa, though some members have it as far west as the IA-NE border. Where this low tracks will determine the precipitation footprint and instability. The eastern low scenario, such as seen in the deterministic GFS, has a plume of IVT up to 500 kg m-1 s-1 advecting into northeast MO/west-central IL while the axis of greatest IVT remains southwest along the IL-KY border. This results in lower QPF totals across the region. In a western low scenario, such as seen in the deterministic ECMWF, QPF increases across the area. While the spread in QPF is still quite large with these scenarios, ensemble means suggest that at least 0.5 inches of rain will be likely (70% chance) area-wide. Similar to QPF, instability will depend on the track of the low. With an eastern low, the axis of greatest MUCAPE is pushed east of the area, while a western low allows for MUCAPE to peak along the MO-IA border into eastern Iowa. Together, these give two potential scenarios: an eastern low that has reduced QPF and thunderstorm chances and a western low with enhanced QPF and thunderstorm chances.

After this embedded shortwave passes through Monday night, zonal flow will return along the southern edge of the upper low. The 500mb jet will remain to the north, leading to broad synoptic subsidence Tuesday and Wednesday. This will allow for another dry and clear period, with temperatures remaining seasonable for late April.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 0100 AM CDT Thu Apr 23 2026

A busy period of weather will occur during this TAF period as thunderstorms develop Thursday afternoon into the overnight hours along a cold front in western IA. VFR conditions are expected to start the period, accompanied with gusty winds starting around 15Z. Thunderstorm potential will increase past 18Z, though some uncertainty remains in whether a pre-frontal cluster will develop, hence the use of PROB30 groups. If these thunderstorms develop, MVFR conditions will occur. Greater confidence remains in a line of thunderstorms passing through CID and DBQ by the end of the period, bringing with them at least MVFR VSBYs and CIGs.

CLIMATE

Issued at 251 AM CDT Thu Apr 23 2026

Record High Temperatures:

April 23: KBRL: 84/1960

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.